vestibular diagnostics VNG and VOG

Contact-free eye tracking applications

Vestibular diagnostic video systems could be used not only in medicine. Currently that equipment is widely used in the following fields: psychology, vision science, ergonomics, driving studies, neuroscience, human factors, web design, ophthalmology, usability, marketing. It's ideal tool to examine reading and visual scanning.

VF5 system can record numerical data and video protocols. Results include pupillometry, fixation control, scan path and distribution, and span of attention.

Applications range from usability evaluations of GUI designs to basic research with parallel EEG recordings. Measurements can be taken from any single planar surface, such as computer monitors, television or projection screens. Recordings can be made under normal office conditions and the system does not require special illumination precautions.

The eye tracking system consists of two main components, computer and mask with built-in videocamera which are easy to transport and set up.

The initial calibration process is performed automatically by software, which is included in the package. The calibration is done in seconds and the system provides immediate feedback about the quality of the calibration. During measurement the operator can control the quality of the eye image and the gaze location at the same time.

Auxiliary information can be recorded together with the eye movements if the stimulus software is adapted to the remote interface. Otherwise, simple TTL trigger inputs may be used. In case of a randomly changing screen content, a video protocol of the stimulus screen and gaze location may be generated by the video-card and recorded in DVD resolution with an integrated MPEG encoder.

The recorded gaze data can be saved in an open data format. It can be used within the analysis software or exported to 3-rd party software. The analysis software provides numerical and graphical analysis functions for quick and effortless data interpretation.

Head Mounted Eyetracking Device - VF5 uses lightweight head mounted cameras which capture the images of the subject's eye and field-of-view. The computed gaze position is overlaid on the environment image and visualized in real-time. The integrated AVI or MPEG video recording capability can be utilized to save the scene video for post-analysis. Alternatively, an external VCR can be connected.

Typical applications are ergonomics, human factors, driving studies, point-of-sale optimizations and other areas where large subject movements are expected.

VF5 system combines all required components for efficient high-quality eye movement and scene video recordings into a single high-performance PC workstation. Real time image processing, calibration, auxiliary device control, data and video recording are all integrated in one easy-to-use application.

VF5 system is provided as a working solution from the day of installation. It is delivered fully integrated, pre-configured, and tested. The adaptation to typical lab settings can be prepared at the factory, so that recording can start immediately.

Principle of Operation

VF5 uses infrared cameras to capture the eye movements. Images of the eye are analysed in real-time with video field rate, resulting in a 25 / 30 Hz sampling rate. Higher sampling rates are available for specific applications. The system locates the pupil and calculates the centre. Several steps of image artefact compensation and noise reduction are implemented.

The procedure of calibrating the subject's eye movement to the environment depends on the camera system being used. Generally, it requires the subject to fixate on several pre-determined points and the system to detect these fixations. VF5 provides fully automated calibration for monitor displays. Calibration time for a subject on the VF5 system is typically measured in seconds.

All functions (eye tracking, stimulus, data acquisition) can be controlled remotely by the operator from a separate computer. For external integration with stimulus events, all recorded data can be accessed on-line via a high-speed interface.

The raw eye movement and pupil diameter data together with the actual gaze position, i.e., as displayed on the monitor, can be synchronized with external stimulus generator and recorded to file. Data export into open formats (ASCII, txt) is as easy as graphical analysis in the integrated software analysis package.

Configurations which include a live video stimulus can record the input signal with gaze position overlay and status information on the internal MPEG recorder with DVD quality. Alternatively, the video signal is available for standard VCRs.

VNG and VOG equipment
Russia, Moscow 129344, Iskra Street 17-A, build. 3
Phone: +7 (495)-542-04-49